We all know that eating foods high in protein helps keep our muscles strong. But did you know that protein can come from both animals and plants - and for decades, one of these protein sources was lauded while the other discarded by serious athletes and weekend warriors just trying to get stronger.
But what if we were wrong?
When you picture people ingesting protein after a workout, what images come to mind? Taking scoops of dusty white powder from a giant jug of whey protein to mix into a drink? Or maybe thick, pre-made protein shakes alchemized from “milk protein isolate”?
Or do you think of snacking on tofu, peanuts, and maybe hummus?
In the past few years, nutrition and exercise research has focused on studying how different sources of protein can benefit muscle growth in our bodies. The data on these findings is relatively new - within the last six years or so - but the results will be especially interesting to vegetarians, vegans, or others who prefer not to rely solely on animal-based proteins.
Many of us associate the word “protein” with meats like chicken, steak, ground beef, and pork. Conventional wisdom says that these animal-based protein sources yield the biggest muscles and the fastest recovery. And so we scooped mounds of whey protein powder into our cold glasses of milk to feed our muscles and grow our biceps.
But with a trending rise in vegetarianism and veganism, athletes are looking to incorporate a variety of protein sources in their diets. But do “alternative” sources of protein match up to the muscle-building capability of something as tried-and-true as animal-based protein?
What Is Protein and Where Is It Found?
Proteins are molecules composed of amino acids that perform multiple duties within our bodies, but in this context, we’re focusing on their ability to heal and grow muscles. In high school science class, you’ve surely heard the phrase building blocks to describe how proteins function within cells. Proteins are found in living tissues, which means humans can eat proteins that exist naturally in animals and animal byproducts or plants and plant byproducts.
For example, we previously mentioned whey protein powder; whey is a byproduct of cheese and casein processing, which makes it an animal byproduct as well. In fact, if you’ve ever opened your yogurt to find a small pool of liquid resting on top, don’t pour it out. That liquid contains important nutrients - including whey and its related proteins - so mix it back in.
Although whey is a few steps removed from the flesh of the animal itself, it is no less effective in muscle growth and recovery. Besides, who wants to throw a steak in a blender and drink puréed meat after a tough workout? In fact, there are many animal-based sources of proteins that can help round out a full, carnivorous diet. Here’s a meaty list originally published in the Huffington Post:
- 65g of beef, pork or lamb or 80g chicken = approximately 20-25g protein
- 1 large egg = approximately 7g protein
- 100g tuna = approximately 30g protein
- 2 slices of cheese = approximately 10g protein
- 100g yogurt = approximately 10g protein
As you can see, protein is found in both animal flesh as well as animal byproducts like cheese and yogurt. We’ve focused on whey so much here because it is currently the popular protein source to study, which we’ll get to later.
So what about the proteins you can get from plants?
Protein Comes From Plants, Too
Now we know that animal flesh is high in protein, but if meat isn’t on your post-workout menu, you’ll see roughly the same protein benefit from a peanut butter sandwich than you will in a baked chicken breast. Here’s a continuation of that HuffPo list from the previous section, but just the plants this time:
- 1 cup cooked quinoa = approximately 8g protein
- 1 tablespoon peanut butter = approximately 6g protein
- 100g tofu = 12-15g protein
- ½ cup of oats = approximately 7g protein
- 2 slices seedy whole grain bread = approximately 12g protein
- 30g nuts, seeds and nut/seed butters = approximately 10-15g protein
- 100-150g legumes = approximately 15-20g protein
Who’d have thought that there was so much protein in oats? This helps make the case that a balanced and diverse diet is optimal if you are trying to increase muscle mass and strength. By adding vegetables, fruits, beans, seeds, and other plants to your diet, you will also benefit from a more complex nutrient palette that isn’t available in meat alone. We’re talking vitamins, minerals, fibers, and more.
The Results Are In
Multiple studies have found that animal-based protein provides the same muscle-building benefits as plant-based proteins. Moreover, a couple of these studies concluded that both plant- and animal-based proteins not only provide similar results, but they both outperformed placebo groups.
For example, this 2015 study from French researchers found that pea proteins performed equally to whey proteins in building the biceps muscles of young men. A study in January of 2019 using Crossfitters as subjects replicated these results. And in 2013, researchers published a study in the Nutrition Journal that found no difference between whey protein isolate and rice protein isolate on body composition and exercise performance.
What Does This Mean For Athletes, Vegetarians, and You?
If you choose to avoid eating animal products, these studies are good news. The main takeaway is that you can successfully get all the protein you need from planted-based sources, even if you are an athlete or trying to add pounds of muscle to your physique. And if you do choose to eat animal products, you should consider adding plant-based proteins to your diet in addition to meat, eggs and dairy for nutrient diversity.
Although nuts, seeds, and grains are clearly a good source of protein, these numbers alone aren’t enough to prove that plant-based proteins are equal to more well-known meat-based proteins. We have to take other factors into account, like allergies or sensitivities, but also digestion and absorption rates. A food can have 1,000g of protein, but it doesn’t matter if your body can’t absorb the molecules and filter the amino acids where they need to go. In fact, if you ingest more protein than your body can process, you’ll waste all that whey powder or soy protein isolate you scooped into a smoothie. Talk to a nutritionist or your primary care physician for advice about your specific dietary needs to ensure that what you eat is helping fuel how you exercise.